Evidences for 17 rak’ats of Isha Salah in the Hanafi Madhhab
A breakdown of the actual rak’ats with evidences:
Four rak’ats Sunna (ghayr mu’akkada) before the Fard Salah:
https://www.darultahqiq.com/four-rakats-isha-prayer-assessment-legitimacy/
Four Rak’ats Fard for Isha:
Jabir ibn Samura (ra) reported: The people of Kufa complained to Umar ibn al-Khattāb about Sa’id and they made a mention of his prayer. ‘Umar sent for him. He came to him. He (‘Umar) told him that the people had found fault with his prayer. He said: I lead them in prayer in accordance with the prayer of the Messenger of Allah (may peace be upon him). I make no decrease in it. I make them stand for a longer time in the first two (rak’ats) and shorten it in the last two. Upon this ‘Umar remarked: This is what I deemed of thee, O Abu Ishaq (Sahih Muslim Book 4, Number 912)
Four Rak’ats after the Fard of Isha:
http://darulmaarif.com/a-forgotten-sunnah/
Three rak’ats Witr:
https://www.darultahqiq.com/hadith-proofs-for-the-hanafi-procedure-of-witr/
Two Rak’ats Nafl after Witr:
Umm Salamah (ra) narrates, “Verily the Prophet (sallallahu alaihi wa sallam) would pray two rak’ats after the witr.” (Jami al Tirmidhi, no.471 and Sunan Ibn Majah, no. 1195)